This specification for the instant application should be granted the priority date of Sep. 21, 2005, the filing date of the corresponding German patent application 20 2005 014 838.5.
The invention relates to a longitudinal cutting machine with an arrangement of upper blades held on a longitudinal guide and displaceable on the longitudinal guide and an arrangement of lower blades associated with the upper blades and held on a further longitudinal guide and displaceable along this longitudinal guide, at least one displacement device being provided for displacing the upper blade and the lower blade.
Such a longitudinal cutting machine with respective upper and lower blades displaceably arranged on associated longitudinal guides is disclosed in DE 100 23 210 B4. In this connection, the longitudinal guide for the upper blades is configured as a cross-member with blade holders for a respective upper blade guided thereon, while the lower blades configured as keyway cutters are displaceable on a lower blade shaft as a longitudinal guide. Insofar as during the operation of such longitudinal cutting machines, it is desirable to alter the cutting width of the webs of material cut by the associated blades, positioning devices are provided with such longitudinal cutting machines. In the longitudinal cutting machine known from DE 100 23 210 B4, a positioning device is firstly provided for the lower blades which respectively acts separately on an associated lower blade and displaces said lower blade into a predetermined position. A relatively complicated measuring and calculating system is provided to move the relevant lower blade precisely into the desired position. Accordingly, a second displacement device associated with the blade holders for the upper blades is activated, which undertakes the displacement of the upper blades into the position corresponding to the position of the lower blades.
When positioning the individual blades, the drawback associated with such a method is that the positioning is very time consuming, not only due to the individual adjustment of the upper blades and lower blades but also that a correspondingly synchronized control of the two displacement devices is required for the lower blades and the upper blades. During the respective adjustment of the upper blades and the lower blades, this may result in inaccuracies so that the upper blades and lower blades do not cooperate with one another with the desired cutting force.
The object of the invention, therefore, is to design a longitudinal cutting machine with the aforementioned features, such that an alteration of the cutting width may be carried out rapidly and with high positioning accuracy by means of corresponding adjustment of the upper blades and lower blades.